Thanks Silyavski, yep that's going to be many many hours of welding. I'm a bit worried that the two square tubes on the front will bend a little during welding as its only welded on three sides but I'm hoping it will be ok. Maybe I'll only weld them top and bottom and not the back to prevent distortion. Do you think I need some ribs on the inside of the I-beam to prevent flex in the Y direction or is it going to be stiff enough with just the bearing and motor mount plates welded in?